Whats wrong here...

[chromyelow1]

This has been going on for a while and have taken to the mechanic and all he does is get a bigger gauge wire. Can anyone explain this to me. My truck turns on really quick and dont have this problom alot, but every once in a while ill be low on gas and and it will not turn on as quick and then the wire starts to melt from the constant cranking. Any input?

[renagadebee34]

there is definitly a short somwhere i cant really help unless i could see more sorry man

[cochino12]

I had a truck acting similar to that and the problem was the main cable, have you tried replacing it?

[454HO]

Not good. The starter is pulling current through that chassis ground instead of the main ground cable that should go directly to the engine block.

[slug]

I Would Replace The Whole Ground Cable And Clean Where It Bolts To The Frame And Core Supp.

[westie 666]

You could try running a ground cable from the motor to chassis and remove the one off the battery to body.

[Russell]

Low voltage = high current. High current = high temperatures across a resistance.

As mentioned above, your truck is grounding the starter through the small cable that goes to your core support. It may be able to survive when your battery is at full voltage and current is relatively low, but as soon as your battery gets low and you don't have much voltage, you get very high amp draw which will make the wire very hot.

I'd imagine that the thick cable is so corroded inside the insulation that it is no longer conducting much if at all.

Stop by Napa and get a brand new cable, polish up the battery post, and both where the skinny wire and the thick wire are mounted onto the core support / engine block to where there is shiny metal showing and your problem should be solved.

[OJOE]

Originally Posted by Russell

Low voltage = high current. High current = high temperatures across a resistance.

As mentioned above, your truck is grounding the starter through the small cable that goes to your core support. It may be able to survive when your battery is at full voltage and current is relatively low, but as soon as your battery gets low and you don't have much voltage, you get very high amp draw which will make the wire very hot.

I'd imagine that the thick cable is so corroded inside the insulation that it is no longer conducting much if at all.

Stop by Napa and get a brand new cable, polish up the battery post, and both where the skinny wire and the thick wire are mounted onto the core support / engine block to where there is shiny metal showing and your problem should be solved.

dats rite. dats what me would do

[78 Chevyrado]

Originally Posted by Russell

Low voltage = high current. High current = high temperatures across a resistance.

As mentioned above, your truck is grounding the starter through the small cable that goes to your core support. It may be able to survive when your battery is at full voltage and current is relatively low, but as soon as your battery gets low and you don't have much voltage, you get very high amp draw which will make the wire very hot.

I'd imagine that the thick cable is so corroded inside the insulation that it is no longer conducting much if at all.

Stop by Napa and get a brand new cable, polish up the battery post, and both where the skinny wire and the thick wire are mounted onto the core support / engine block to where there is shiny metal showing and your problem should be solved.

What he said....

Kenny

[andresco50]

Replace the two cables

[69face]

on my new 85 i had the same exact problem. initially i suspected the starter, but that wasnt it. next i suspected the positive cable, not it either. then i suspected a poor engine to body ground, nope not it either. so i cleaned every single ground point and installed a new ground cable and ground strap. the truck even runs better now. good luck!

[72lb4x4]

"Low voltage = high current" is wrong, but there is a problem with the large ground cable or connection as stated...

[Slammed '87]

"Low voltage = high current" is wrong, but there is a problem with the large ground cable or connection as stated...

How so?

[72lb4x4]

A large current from the battery, through the large positive wire to the starter can't flow through the large negative cable back to the battery, so its flowing through the little wire and burning it up. So either the negative cable is bad, or there's a bad ground connection at the engine.

Volts divided by resistance equals current. If you reduce voltage, you reduce current. Its Ohm's Law.

[Russell]

72lb4x4 is correct, I made a mistake with regards the voltage vs current relationship, low voltage should also equal low current. It is described by ohm's law, which is E = IR, or voltage is equal to current times resistance. Rearrange that to solve for current and you get voltage divided by resistance.

If you have 6 volts divided by 1000 ohms you get 6 miliamps, make it 12 volts divided by 1000 ohms, and you get 12 miliamps.

Sorry about that mistake... I'm not an electrical expert by any definition of the phrase!

[chromyelow1]

all i can say is WOW! thanks for the help guys, the truck actually left me stranded today. The wire actually burned and gave out, but now when i replaced it just to give me on last start there was no fuel at the carbuator. how would that happen?

[vintagesteel]

Originally Posted by chromyelow1

all i can say is WOW! thanks for the help guys, the truck actually left me stranded today. The wire actually burned and gave out, but now when i replaced it just to give me on last start there was no fuel at the carbuator. how would that happen?

That would be MURPHY'S law. Ohm's law, murphy's law, you must be a MAN OF THE LAW!

[Longhorn321]

Several have quoted Ohms law correctly so I won't go into that but I will add a way to test for this condition that has been described where there is too much resistance in the big cable. If you just replace the cable, you will probably fix the truck as far as starting goes but if you want to confirm your suspisions (our suspisions), take a volt meter and put the red lead on the engine block (clean metal) and put the black lead in the center of the neg. post. Hit the starter....when the higher current goes through the cable, if there is resistance there, there will be a voltage drop and you will see voltage on your meter. Resistance = voltage drop! If you see voltage on your meter, you have some resistance! The higher the voltage, the higher the resistance. The resistance becomes a load when you throw the juice for the starter through it. You will have a voltage difference from one end of the cable to the other and you don't want that.

[Longhorn321]

As far as the fuel problem goes, unless you have an electric pump, it has nothing to do with your battery cable/starting problem. Take the inlet hose off and put your thumb on the fitting of the fuel pump and have some one crank the engine. If you don't feel some vacuum, replace the fuel pump. $20 at Advance auto for a SBC.

[mhicks]

Be sure and connect a wire to the chassis and clean the connection where it connects to the chassis with a wire brush real good. You have got to have that good chassis ground or you will have other headaches.

[babyJay]

What is wrong? You havn't fired your mechanic and hired a new one yet